Elbow formation apparatus

ABSTRACT

An apparatus for forming and rotating interconnected sections of a cylindrical sheet metal workpiece to provide an elbow. The apparatus includes a frame, a head rotatably arranged within the frame and a tool ring mounted to the frame, the head and tool ring being co-operable for sectioning and joining segments of the workpiece. The apparatus also includes a drive drum mounted within the frame for gripping and rotating the segments, and a control module for selectively activating the head, the ring, and the drive drum to form an elbow.

CROSS-REFERENCE OF RELATED APPLICATION

WO This application claims the benefit of U.S. Provisional ApplicationSer. No. 61/143253, filed on Jan. 8, 2009, and herein incorporated byreference in its entirety.

FIELD OF THE INVENTION

This invention relates, in general, to a formation and rotationapparatus for use in forming and rotating interconnected sections of acylindrical workpiece, and deals more particular with a formation androtation apparatus that will automatically form and turn each section ofcylindrical workpiece to its proper orientation even in the cases oflarge diameter elbow workpieces.

BACKGROUND OF THE INVENTION

Elbow sections of ductwork are typically formed as straight pieces ofcylindrical ductwork prior to being manipulated into a finished elbowhaving a substantial bend attributed thereto. This manipulation hastraditionally been accomplished by hand.

While the known hand manipulation of elbow workpieces is effective to acertain degree, such a process is manually difficult and time consuming,as well as oftentimes resulting in the formation of finished elbowshaving slightly non-uniform characteristics.

Additional complications arise when large diameter elbow workpieces areutilized.

With the forgoing problems and concerns in mind, it is the generalobject of the present invention to provide a dual head elbow rotatorapparatus that will automatically form and rotate large diametersections of an elbow workpiece to form the finished elbow.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an elbow rotatorthat will automatically turn each section of an elbow duct to theirproper orientations.

It is another object of the present invention to provide an elbowrotator that will automatically turn each section of an elbow duct totheir proper orientations while being incorporated into an elbowformation apparatus.

It is another object of the present invention to provide an elbowrotator that will automatically turn each section of an elbow duct totheir proper orientations while serving as a stand-alone apparatus.

It is another object of the present invention to provide an elbowrotator that will simultaneously rotate each integrally formed sectionof an elbow workpiece.

It is another object of the present invention to provide a dual headelbow rotator apparatus.

It is another object of the present invention to provide a dual headelbow rotator apparatus, which can balance the forces incident upon theelbow workpieces during formation.

It is therefore an important aspect of the present invention to proposea formation and rotation apparatus for use in forming and rotatinginterconnected sections of a cylindrical sheet metal workpiece,including a frame, a head rotatably arranged within the frame, the headcarrying at least one cutting wheel and at least one beading wheel, atool ring mounted to the frame and carrying rollers operable with thewheels for sectioning and joining segments of the workpiece, a drivedrum mounted within the frame for gripping and rotating the segments,and a control module for selectively activating the head, the ring, andthe drive drum to form an elbow.

These and other objectives of the present invention, and their preferredembodiments, shall become clear by consideration of the specification,claims and drawings taken as a whole.

Another alternative embodiment relates, in general, to an elbow rotatorapparatus, and deals more particularly with an elbow rotator apparatuswhich is capable of handling workpieces of varying diameters, sectioningthese workpieces, and rotating them into finished elbow units, or thelike.

Elbow sections of ductwork are typically formed as straight pieces ofcylindrical ductwork prior to being manipulated into a finished elbowhaving a substantial bend attributed thereto. This manipulation hastraditionally been accomplished by hand.

While the known hand manipulation of elbow workpieces is effective to acertain degree, such a process is manually difficult and time consuming,as well as oftentimes resulting in the formation of finished elbowshaving slightly non-uniform characteristics.

Automated systems have also been proposed to accomplish the rotation ofthe individual elbow sections of a workpiece; however, these proposedsystems cannot perform their operation over a wide range of elbowworkpieces that may vary in diameter.

With the forgoing problems and concerns in mind, it is the generalobject of the present invention to provide an elbow rotator that willautomatically form and rotate individual sections of an elbow workpiece,regardless of the diameter of the elbow workpiece, or the difference indiameter between subsequent processes.

It is an object of the present invention to provide an elbow rotatorthat will automatically form and turn each section of an elbow duct totheir proper orientations.

It is another object of the present invention to provide an elbowrotator that will automatically turn each section of an elbow duct totheir proper orientations while being incorporated into an elbowformation apparatus.

It is another object of the present invention to provide an elbowrotator that will automatically turn each section of an elbow duct totheir proper orientations while serving as a stand alone apparatus.

It is another object of the present invention to provide an elbowrotator that is capable of accommodating elbow workpieces of varyingdiameters.

These and other objectives of the present invention, and their preferredembodiments, shall become clear by consideration of the specification,claims and drawings taken as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a straight elbow section of ductwork, or elbowworkpiece, having a plurality of integrally formed sections.

FIG. 2 illustrates a finished elbow section of ductwork.

FIG. 3 is partial cross-sectional view of an elbow machine having anelbow rotator, wherein the elbow workpiece is in a first position,according to one embodiment of the present invention.

FIG. 4 is partial cross-sectional view of an elbow machine having anelbow rotator, wherein the elbow workpiece is in a second position,according to one embodiment of the present invention.

FIG. 5 is partial cross-sectional view of an elbow machine having anelbow rotator, wherein the elbow workpiece is in a finished position,according to one embodiment of the present invention.

FIG. 6 is partial cross-sectional view of an elbow machine having anelbow rotator, wherein the elbow rotator is tilted back to permitremoval of the finished elbow unit, according to one embodiment of thepresent invention.

FIG. 7 is a front, partial cross-sectional view of the elbow rotator ofthe present invention.

FIG. 8 is a top, partial cross-sectional view of the elbow rotator ofthe present invention.

FIG. 9 is a side, partial cross-sectional view of the elbow rotator ofthe present invention.

FIG. 10 is partial cross-sectional side view of a freestanding elbowrotator, according to another embodiment of the present invention.

FIG. 11 is a partial cross-sectional end view of a gripping arm of thefreestanding elbow rotator in its ‘up’ position.

FIG. 12 is a partial cross-sectional top view of the gripping arms ofthe free standing elbow rotator in their ‘down’ position and securedabout their respective sections of the elbow workpiece.

FIG. 13 is a partial cross-sectional side view of the gripping arms ofthe free standing elbow rotator after rotation back to their ‘up’position, thereby forming a completed elbow.

FIG. 14 is a partial cross-sectional end view of a gripping arm of thefreestanding elbow rotator.

FIG. 15 illustrate the gripping arm of FIG. 14 as it accommodates elbowworkpieces of differing diameters.

FIG. 16 is a partial cross-sectional end view of the gripping arms ofthe free standing elbow rotator in both its ‘up’ and ‘down’ positions.

FIG. 17 illustrates a dual-slide block cutting and beading apparatus, inaccordance with another embodiment of the present invention.

FIG. 18 illustrates a side view of a dual slide-block head utilized inthe dual-slide block cutting and beading apparatus of FIG. 17, inaccordance with one embodiment of the present invention.

FIG. 19 illustrates a partial cross-sectional top view of a dualslide-block head shown in FIG. 18.

FIGS. 20-23 illustrate various perspective views of a fully-assembledtop-loading elbow cutter and rotator according to a further embodimentof the present invention.

FIGS. 24-27 illustrate various casing-removed perspective views of theelbow cutter and rotator shown in FIGS. 20-23.

FIG. 28 illustrates an assembled view of a tool ring subassembly of theelbow cutter and rotator shown in FIGS. 20-27.

FIG. 29 illustrates an exploded assembly view of an improved bead/lockshoe or slide block head for use in the elbow cutter and rotator shownin FIGS. 20-27.

FIG. 30 illustrates an exploded assembly view of a drum drivesubassembly of the elbow cutter and rotator shown in FIGS. 20-27.

FIG. 31 illustrates a perspective view of an arbor head and arbor columnof the elbow cutter and rotator shown in FIGS. 20-27.

FIG. 32 illustrates an exploded assembly view of an arbor head of theelbow cutter and rotator shown in FIGS. 20-27.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a section of an elbow ductwork 10 prior to the elbow10 being rotated into its final form. As can be seen in FIG. 1, theelbow 10 includes several sections 12 that have been formed by bending asheet-metal workpiece, or the like, into a cylindrical shape about acommon seam 14. Each of the sections 12 are separated from one anotherby an elbow joint 16 which has been cut and formed in the elbow 10 in amanner well known in the art. As will be appreciated, each of thesection 12 of the elbow 10 shown in FIG. 1 must be turned with respectto one another in order to form the finished elbow 18, shown in FIG. 2.

As illustrated in FIG. 2, and in contrast to the elbow workpiece shownin FIG. 1, the seam 14 is no longer continuous along the length of thefinished elbow 18 due to the individual rotation of the sections 12.During rotation, it is typical that each of the sections 12 experiencean approximately 180° rotation with respect to adjacent sections inorder to provide the ‘bend’, typically approximately 90°, to thefinished elbow (as shown in FIG. 2). The present invention provides aheretofore-unknown apparatus having the ability to automate the rotationof the individual sections 12 of an elbow workpiece.

It should be noted that while a rotation of approximately 180° has beendescribed, other angles of rotation may also be accomplished withoutdeparting from the broader aspects of the present invention.

FIG. 3 illustrates an elbow machine 20 equipped with an elbow rotator 22of the present invention. As shown in FIG. 3, an elbow workpiece 24 ismounted within the elbow machine 20 after the elbow workpiece 24 hasbeen formed by the elbow machine 20 in accordance with a known process.A first section 26 of the elbow workpiece 24 is then rotated by theelbow rotator 22, as shown in FIG. 3, in a manner to be explainedshortly. FIGS. 4 and 5 illustrate the subsequent rotation, andcorresponding re-orientation, of additional sections of the elbowworkpiece 24 by the elbow rotator 22. FIG. 6 illustrates the finishedelbow workpiece 24 and, in phantom, a new elbow workpiece 28 beingmounted for similar processing.

The elbow rotator 22 is preferably mounted on an inclined work surface30 of the elbow machine 20 so as to accept and automatically manipulateeach section of the elbow workpiece 24 as each joint of the elbowworkpiece 24 is formed by the elbow machine 20. FIG. 7 is a front,partial cross sectional view of the elbow rotator 22. As shown in FIG.7, the elbow rotator 22 includes a pair of gripping arms 32 havingflexible, resilient pads 34 disposed on the ends thereof. A hydrauliccylinder 36, or the like, is utilized to close the gripping arms 32about a lead section of the elbow workpiece 24. As will be appreciated,the gripping arms 32 will grip the elbow workpiece 24 with a forcecommensurate with the hydraulic pressure applied to the cylinder 36.Moreover, the cylinder 36 is disposed between the gripping arms 32 anddoes not control the position of the gripping arms 32, which will centerthemselves about and on the elbow workpiece 24 as the elbow workpiece isbeing rotated. As is also shown in FIG. 7, a frame 38 is rotatablymounted on the inclined work surface 30 about pivot joints 40 andsubstantially supports elbow rotator 22.

It will be readily appreciated that while hydraulic cylinders have beendiscussed in connection with the present invention, other alternativedesigns, such as but not limited to pneumatic systems, may be utilizedwithout departing from the broader aspects of the present invention.

FIG. 8 illustrates a top, partial cross-sectional view of the elbowrotator 22. As seen in FIG. 8, the gripping arms 32 are mounted to agripping frame 42, which selectively pivots about an axis A that issubstantially perpendicular to the plane of the joint and is centered onthe axis of the joint. The gripping frame 42 is rotated by a rollerchain 44 driven by a rotary actuator 46. The rotary actuator 46 willselectively cause the frame 42 and gripping arms 32 to rotateapproximately 180°. A sprocket 48 is located on the rotary actuator 46includes more teeth than a similar sprocket 50 located on the frame 42in order to provide rotation of more than 180°, should such a rotationbe desired. Stroke limiters are utilized on the rotary actuator 46 toadjust the amount of rotation that is produced. Moreover, an adjustabletorque limiter 52 is utilized in conjunction with the rotary actuator 46to limit the available torque that will rotate the elbow workpiece 24.

In operation, each section 12 of the elbow workpiece 24 is sequentiallygripped by the gripping arms 32 and rotated approximately 180° under thedirection of the rotary actuator 46. After each section 12 of the elbowworkpiece 24 has been rotated, the rotary actuator 46 is returned to itshome position. The gripper frame 42 rotates back by only the amount over180° that a given section 12 of the elbow workpiece 24 may have beenrotated. In such instances, the gripper frame 42 is stopped by a ratchetand pawl wheel assembly 54 (seen in FIG. 9) at the 180° position, whiletorque limiter 52 slips to allow the rotary actuator 46 to continuerotating to its home position. In this manner, each successive section12 of the elbow workpiece 24 may be rotated in the same direction and,moreover, the direction of rotation may be easily reversed by changingthe configuration of the ratchet and pawl assembly 54 and reversing thehome position of the rotary actuator 46. In this regard, there is apreferred direction to rotate the sections 12 of the elbow workpiece 24depending on which direction the seam 14 is lapped so that the seam 14will not catch. In order to achieve proper positioning, it may also benecessary to rotate the first section 12 of the elbow workpiece 24 morethan 180°, as the first section 12 of the elbow workpiece 24 may havebeen slightly rotated during formation of the joints 16.

FIG. 9 illustrates a side, partial cross-sectional view of the elbowrotator 22. As seen in FIG. 9, the elbow rotator 22 includes a hydraulicpositioning cylinder 56, which selectively causes the elbow rotator 22to pivot about pivot joints 40. Indeed, as best seen with reference toFIGS. 9 and 6, the frame 38 along with the gripping arms 32 and rotaryactuator 46 may be selectively tipped back at the conclusion of eachelbow production cycle (the position illustrated in FIG. 6) so as toprovide enough clearance to remove the finished elbow from the elbowmachine 20 and insert the new elbow workpiece 28. The frame 38 wouldthen be tilted back to its operative position to ready for the nextelbow production cycle.

It will be readily appreciated that the elbow rotator 22 of the presentinvention may automatically and sequentially rotate differing sectionsof a formed elbow workpiece to their proper orientation without the needfor manual manipulation of the same. The production of finished elbowunits may therefore be substantially increased as compared to manualproduction methods currently in use. Moreover, given that the elbowrotator 22 resets to a known ‘home position’ prior to each rotation, andfurther, that the elbow rotator 22 may even compensate for the slightrotation of the first section of the elbow workpiece, the presentinvention is capable of repetitively producing finished elbow unitshaving substantially uniform characteristics and mechanical tolerances.

While FIGS. 3-9 illustrate the elbow rotator 22 being integrated withthe elbow formation machine 20, the present invention is not limited inthis regard. Indeed, the present invention contemplates a free standingelbow rotator apparatus that is not integrated with another device orapparatus, rather it may be a wholly separate unit for accomplishing thesame general task as the elbow rotator 22, discussed above.

FIG. 10 illustrates a partial cross-sectional side view of afreestanding elbow rotator 60, in accordance with another embodiment ofthe present invention. As shown in FIG. 10, the freestanding elbowrotator includes a housing 62 and an inclined work surface 64 containedtherein.

As discussed previously, adjustable elbow workpieces are initiallymanufactured as straight tubes having a series of integrated sections.After an elbow machine has finished making the joints in an elbowworkpiece 24, it is still in a straight shape (as seen in FIG. 1). Theelbow workpiece must then be rotated into its angled configuration andjoined together with other elbows to form a “donut”. This donutarrangement is the preferred method of shipping elbows for manymanufacturers.

A 90-degree elbow 24 consists of four sections 12, such as shown in FIG.2. As mentioned previously, each section 12 must be rotatedapproximately 180 degrees relative to the adjacent sections 12 toposition the elbow in its 90-degree shape. There are other elbowconfigurations that have fewer sections and may result in differentangles of the rotated elbow, but all typically require the 180 degreerotation of the adjacent sections in order to produce a finished, orcompleted, elbow configuration.

Returning to FIG. 10, the freestanding elbow rotator 60 further includesa pair of gripping arms 66 and 68. Each of the gripping arms supportsseveral pairs of gripping fingers 70 and is oriented for selectiverotation about rotational axis R. In operation, the gripping fingers ofthe gripping arms will selectively secure about each section 12 of theelbow workpiece and rotate them to their finished orientation, as willbe described in more detail hereinafter. While the free standing elbowrotator has been described as having several pairs of gripping fingersfor each of the gripping arms, the present invention is not limited inthis regard as the gripping arms may alternatively support any number ofpairs of gripping fingers, inclusive of a single pair, without departingfrom the broader aspects of the present invention.

It is therefore an important aspect of the present invention that onepair of the gripping fingers 70 will rotate each of the sections 12 sothat all of the sections 12 can be turned at the same time. In thismanner, the freestanding elbow rotator 60 of the present inventionserves to significantly reduce the manufacturing time of elbowworkpieces, especially as contrasted with the previously known manualrotation of the sections of the elbow workpiece 24.

As further shown in FIG. 10, and with the gripping arms 66 and 68 intheir ‘up’ position, an operator will load a straight elbow workpiece 72into the free standing elbow rotator 60, from the front andsubstantially in a direction L. The straight elbow workpiece ispreferably loaded so as to ensure that the seam 14 is up and the crimpedend out.

Once a start button is pushed, the straight elbow workpiece 72 is swungup to re-position the straight elbow workpiece at a second, inclinedposition 74 within the free standing elbow rotator 60. Thus, thelongitudinal axis of the straight elbow workpiece will be arrangedsubstantially parallel with, and preferably concentrically aligned with,the rotational axis R of the gripping arms 66 and 68. FIG. 11 is apartial cross-sectional view of the straight elbow workpiece as it isarranged within the free standing elbow rotator with the gripping arms,and gripping fingers 70, in their ‘up’ position.

A cam and roller arrangement permits each of the gripping arms 66 and 68to pivot as they rotate down. As each of the gripping arms reach their‘down’ position, each of the gripping fingers 70 will contact anadjustable stop 76 to arrest each of the gripping fingers in the properstarting position to grip the sections 12. The stops are manuallyadjustable to produce the correct amount of rotation to each of thesections.

With the gripping arms 66 and 68 in their ‘down’ position, the grippingarms 70 are caused to close about each section 12 of the elbow workpiece74. As shown in FIG. 12, the gripping fingers contacting adjacentsections are alternately connected to gripping arms 66 and 68. That is,on a four-section elbow workpiece, the first and third section grippingfingers are mounted on one gripping arm, and the second and fourthsection gripping fingers are mounted on the other gripping arm. FIG. 12illustrates the free standing elbow rotator 60 when the gripping armsare in their ‘down’ position, and the gripping fingers are each securedabout their respective sections of the elbow workpiece.

After gripping each of the sections 12, one gripping arm 66 or 68rotates ninety (90) degrees clockwise while the other gripping arm 68 or66 rotates approximately ninety (90) degrees counterclockwise. As thearms rotate, they swing out approximately fifteen (15) degrees to followthe arching movement caused by rotating the angled joints 16 of theelbow workpiece 74. Each set of the gripping fingers 70 is mounted tothe gripping arms by a pivoted joint so the gripping fingers may twistwith each section of the elbow workpiece as it is rotated. The rotationsof the two gripping arms are synchronized by a chain and sprocketassembly operatively connected to two shafts 78 that are gearedtogether, as shown in FIG. 12. The rotation of the gripping arms therebycauses the individual sections of the elbow workpiece to rotate to theirfinal position and thus define a completed elbow 60. FIG. 13 illustratesa side, partial cross-sectional view of the completed elbow workpiece 80once the gripping arms 66 and 68 have completed their upwards rotation.

Once the gripping arms 66 and 68 have been fully rotated to occupy onceagain their ‘up’ position, as shown in FIG. 13, the gripping fingers 70release the completed elbow 80. The completed elbow is then pivoted, inopposition to the direction in which it was initially loaded, forsubsequent removal from the housing 62 of the freestanding elbow rotator60.

FIG. 14 illustrates an end view of one set of the gripping fingers 70attached to one of the gripping arms 66 or 68. As shown in FIG. 14, thedistal ends of the gripping fingers are each equipped with a resilientand elastic cushioning bumper 82, such as but not limited to a urethanebumper or the like, for protecting the body of the elbow workpiece 74during operation of the free standing elbow rotator 60. A pneumaticcylinder 84, or the like, is utilized to selective cause the grippingfingers to alternatively expand and constrict about the body of theelbow workpiece.

Moreover, as shown in FIG. 15, the gripping fingers 70 of the grippingarms 66 and 68 may be selectively configured to match elbow workpieces72/74 of differing diameters. That is, by changing the attachment points86 of the gripping fingers to the gripping arms, as well as by changingthe attachment points 88 of the gripping fingers to the cylinder 84itself, it is thus possible to accurately accommodate elbow workpiecesof differing diameters. As discussed hereinafter, at least one of thegripping arms also includes a sliding bar 90 which may be selectivelypositioned, via friction bolts or the like, to extend a predetermineddistance, thus selectively abutting adjustable stop 76 and arrestingthereby the rotation of the gripping arms during its downward rotation,as illustrated in FIG. 16.

It will be readily appreciated that when the elbow joints 16 (shown inFIG. 1) are formed in an elbow machine, the sections 12 are usuallyrotated slightly out of alignment with respect to one another. Eachsection 12 must therefore be rotated a different amount to have theproper alignment at the end of the rotation. As discussed above, thepresent invention envisions that one pair of gripping fingers 70 on eachgripping arm 66 or 68 is mounted on a sliding bar 90 so that it may bestopped before the gripping arm is fully rotated down. When the grippingarm is rotated down, it is stopped at a different starting position tomatch the starting position of its respective elbow section. Thegripping arm is therefore stopped at the position for the slidinggripping fingers to match the starting position of its respective elbowsection. As the gripping arm rotates up, only those sections gripped bythe fixed gripping fingers are initially rotated, until the gripping armreaches the position that the sliding gripping fingers was stopped. Asthe rotation continues, the sliding gripping fingers, along with thefixed gripping fingers, now also rotate their respective sectionsthrough the rest of the rotation. At the end of the arm rotation eachsection is therefore in its proper, final position.

It will therefore be appreciated that the present invention provides arotator for elbow workpieces which automatically performs the rotationof respective sections of the elbow workpiece, thereby automating whathas traditionally been a laborious, difficult and time consumingprocess. Moreover, the present invention has envisioned that the elbowrotator may be provided in conjunction with an elbow forming machine,thus rotating each section of the elbow workpiece as it is formed, oralternatively, that a free standing elbow rotator may be utilized forsimultaneously accomplishing rotation of all of the sections of an elbowworkpiece after it has been formed.

While rotation apparatuses for automatically rotating interconnectedsections of pre-formed cylindrical workpieces has been described inconnection with FIGS. 1-16, another embodiment of the present inventioninvolves the utilization of dual cut and bead slide blocks, as depictedin FIGS. 17-19.

Prior art elbow formation methods rely upon the manual manufacture ofelbow sections for large diameter workpieces. Indeed, for workpieceslarger than approximately 18″, each section of the elbow must be madeseparately and manually, and then manually joined together to form thefinished elbow section of duct. Thus, the manipulation oflarger-diameter cylindrical workpieces during the formation of theinterconnected sections is oftentimes cumbersome, owing to the increaseddiameter of the workpiece, and must be preformed manually.

In general, and as discussed previously in conjunction with FIGS. 1-16,automatic elbow machines process straight tubes, that is, cylindricalworkpieces, into segmented adjustable elbows. A cylindrical workpiece isinserted into the elbow machine around a center arbor and is clamped ina set of dies around the outside diameter. These known apparatusesutilize a revolving head mounted on top of the center arbor. A singleslide block is mounted in a slot in the head, and rotates with the head.This single slide block is used to cut and form the interlocking elbowjoints or sections. As known in the art, the slide block typically has acutting wheel disposed at one distal end and a beading wheel disposed atthe other distal end. As the revolving head rotates, the slide block isextended out in one direction to cut through the tube and then out inthe other direction to bead the sections together.

When the slide block is extended out in either working position, thehead is unbalanced, and this is only more of a concern onlarger-diameter workpieces where the single slide block is inherentlylonger and heavier. That is, as the cutting and/or beading wheels areworking the material, the cylindrical workpiece is pulled toward theslide where the slide block is either cutting or forming the material ofthe workpiece. Thus, the performance of known single-slide block formingapparatuses oftentimes suffers accordingly.

The present invention therefore proposes using a head having twoidentical and complimentary slide blocks, in order to better balance theforces exerted upon the workpiece during cutting and bead-formationoperation. FIG. 17 illustrates a side view of a dual-slide block cuttingand beading apparatus 100, according to one embodiment of the presentinvention. The dual-slide block cutting and beading apparatus 100includes a frame 102, within which is supported an elevating assembly104 for selectively moving a cylindrical workpiece along a vertical axisV. A dual slide-block head 106 is arranged adjacent an inclined worksurface 108 of the frame 102, and operates in the manner to be discussedhereafter to cut and form interconnected section of the cylindricalworkpiece.

It will be readily appreciated that the frame 102 and the elevatingassembly 104 of the dual-slide block cutting and beading apparatus 100perform substantially akin to those devices already known in the art,and so further detailed discussion as to their specific components andoperation will be committed to the knowledge of those of such skill inthe art. Suffice to say that the elevating assembly 104 may accept andindex a portion of a cylindrical workpiece disposed within thedual-slide block cutting and beading apparatus 100, so as to present thecylindrical workpiece to the dual slide-block head 106 of the presentinvention.

FIGS. 18 and 19 illustrate a side and a partial cross-sectional topview, respectively, of the dual slide-block head 106, in accordance withone embodiment of the present invention. As shown in FIGS. 18 and 19,the dual slide-block head 106 includes a first and a second slideblocks, 110 and 112, disposed within matching slots 114 of the head 106.

Each of the slide blocks 110 and 112 will have a cutting wheel 116disposed at one distal end, and a beading wheel 118 disposed at theother distal end thereof. The slide blocks 110 and 112 are mounted sideby side in the head 106 and are positioned adjacent the inclined worksurface 108. As best shown in FIG. 19, the slide blocks 110 and 112 willbe oriented such that the cutting wheel-end 116 (and the beadingwheel-end 118) of each slide block is disposed on opposite sides of thehead.

That is, it is an important aspect of the present invention that thecutting wheel 116 of the first slide block 110 is oriented such that itis disposed on one lateral side of a drive gear assembly 120, while thecutting wheel 116 of the second slide block 112 is disposed on the otherlateral side of the drive gear assembly 120. The beading wheel of theslide blocks 110 and 112 are also disposed on alternate lateral sides ofthe drive gear assembly 120, as shown in FIG. 19.

With the configuration as shown in FIG. 19, the dual slide-block head106 effectively balances the forces incident upon a cylindricalworkpiece as the slide blocks 110 and 112 are extended in oppositedirections to cut and to bead the material of the cylindrical workpiece.A drive shaft 122 is located in the center of the dual slide-block head106 and operates the drive gear assembly 120 in order to selectivelydrive matching gears 124 under each of the slide blocks 110 and 112. Thegears 124 located under the slide blocks 110 and 112 will have a pinthat is located at a distance from the center that will drive the slideblocks 110 and 112 back and forth in the head as it turns, thusalternatively forming both a cut in the material of the cylindricalworkpiece, and also the bead that retains one cut portion to another, ina manner well known in the art.

As discussed generally above, using the two slide blocks 110 and 112moving in opposite directions will keep the head 106 balanced and willcontact the cylindrical workpiece on opposing sides to keep thecylindrical workpiece centered. Each wheel 116 and 118 of each of theslide blocks 110 and 112 will be doing half of the cutting or formingwork, so each slide block 110 and 112 can therefore be extended andretracted faster to reduce the overall cycle time. Moreover, it has beendiscovered that he head 106 can also be rotated faster with the balancedweight of the two slide blocks 110 and 112 extended on opposite sides.In the end, a cut and seamed cylindrical workpiece, such as shown inFIG. 1, may be produced in less time, and with greater mechanicalprecision and within greater tolerances than would otherwise be capablewith the known single-slide blocks typically employed in such machines.

Thus, the dual head elbow rotator apparatus shown in FIGS. 17-19 notonly permits the automated manufacture of elbow sections of duct from astraight workpiece, but does so in a manner that balances the forcesincident upon the workpiece during the formation process. In thismanner, the manipulation of larger diameter cylindrical workpieces maybe automated, while also meeting more exacting mechanicalspecifications.

Still further, the dual slide block 106 of the dual-slide block cuttingand beading apparatus 100 produces less vibration, thus resulting in areduced chance of producing slivers, as well as producing a faster cutand reduced total cycle time.

Still yet another embodiment of the present invention resides inequipping a elbow rotator apparatus that includes four (4) or moreopposing cutting and beading slide blocks, preferably disposed every90°, or the like.

It will of course be recognized that the automatic rotational assembliesdescribed in connection with FIGS. 3-16 may be stand-alone devices, ormay be advantageously combined with the dual slide block apparatusesdiscussed in connection with FIGS. 17-19. When so combined, theresultant assembly may quickly and efficiently form the interconnectedsections of a cylindrical workpiece, while subsequently rotating theseinterconnected sections so as to form a desired configuration, such asan elbow configuration.

Referring now to FIGS. 20-32, the present invention may be embodied in atop-loading elbow cutter and rotator 1000 for working an elbow workpiece24. The top-loading elbow cutter and rotator comprises a barstock frame1001 supporting a lower casing 1012 defining a vertical axis andsupporting an upper casing 1014 defining a tube axis. The elbow cutterand rotator also includes a top plate 1002 mounted to the upper casing.As can be seen by reference to FIG. 20, the tube axis defined by theupper casing is tilted at a tube angle about thirty (30) degrees“forward” from the vertical axis defined by the lower casing. The topplate includes a substantially circular through-hole 1021, which definesa cut axis, for receiving the elbow workpiece. As can best be seen byreference to FIG. 23, the cut axis defined by the top plate is furthertilted at a cut angle of about fifteen (15) degrees forward from thetube axis defined by the upper casing 1014, for an overall tilt of aboutforty five (45) degrees between the cut axis and the vertical axis. Theelbow cutter and rotator also includes a multi-diameter tool ringsubassembly 1003 mounted on the top plate coaxial with the through-hole,a quick-change bead/lock shoe 1004 slidably connected to the tool ring,a mounted drum drive subassembly 1005 mounted within the frame coaxialwith the tool ring subassembly, a baseplate 1016 mounted within theframe below the drum drive, an arbor column 1006 mounted on thebaseplate and extending perpendicularly upward from the baseplateapproximately to the center of through-hole in the top plate (andthereby being angled at about fifteen (15) degrees from the cut axisdefined by the through-hole), a fifteen (15) degree arbor headsubassembly 1007 rotatably mounted at the upper end of the arbor columnwithin the through-hole (with the plane of the arbor head being parallelwith the plane of the top plate), a quick-change slide block 1008radially slidably mounted on the arbor head, and a control module 1015for coordinating operations of the tool ring, the drum drive, the arborcolumn, and the arbor head. The tool ring, the drum drive, the arborcolumn, the arbor head, and the slide block cooperate to cut the elbowworkpiece into angled sections, to bead the section edges, and to rotatethe sections to form an “elbow”, “bent leg”, or partial “donut” ofductwork including a plurality of bends ranging from zero (0) to thirty(30) degrees.

Preferably, the tool ring 1003 is adapted to receive one of severalquick-change bead/lock shoes 1004, the drum drive 1005 includesdiametrically adjustable components, and the arbor head subassembly 1007is adapted to receive one of several interchangeable slide blocks 1008,for handling, cutting, and forming several different diameters of elbowworkpieces (seamed sheet metal tubes or thin-walled seamless metalpipes). For example, the tool ring 1003 and the drum drive 1005 can beadjustable for cylinder diameters from four (4) to seven (7) inches,while interchangeable bead/lock shoes 1004 and slide blocks 1008 can beprovided at half-inch (0.5″) diameter increments.

Referring to FIG. 28, the multi-diameter tool ring subassembly 1003includes a base ring 1301, a plurality of mounting brackets 1302extending outward from the base ring for mounting the base ring to theupper plate 1002, a slotted ring 1303 rotatably mounted within the basering, a ring motor 1304 drivingly connecting the slotted ring to thebase ring via a right-angle worm-and-pinion 1305 and a curved rack 1306,and at least one bead/lock shoe 1004 radially slidingly mounted on thebase ring and operatively connected to a spiral slot of the slottedring. The tool ring subassembly 1003 is designed to handle a range of ODpart (for example, 4″ thru 7″ OD elbows) with quick tool changeover. Forexample the spiral slots of the slotted ring 1303 can be angled to shifteach bead/lock shoe 1004 from a 4″ OD position to a 7″ OD position by aninety (90) degree clockwise rotation of the slotted ring. The slotteddisc design allows for high load carrying in both the lock shoe toolsand the lock part tools by simple rotation of a disc as to move the setof tools to the location necessary to perform their function.

Referring to FIG. 29, alternatively, a sequence of interchangeablebead/lock shoes 1004 can be provided in sequential base OD dimensions of4″, 5″, and 6″, with the slots of the slotted ring being angled toaccommodate a range of incremental bead/lock shoe positions from, forexample, −0.1″ OD to +1.1″ OD. Thus a combination of bead/lock shoe andslot position can be selected to accommodate any elbow workpiece sizeranging from 4″ to 7″ OD. Each of the interchangeable bead/lock shoes1004 includes a tracked plate 1401 supporting a slotted block 1402. Theslotted block is covered by a cover plate 1403 and is housed betweengrooved sideplates 1404 a and 1404 b. The slotted block is engaged by apin (not shown) to the spiral slot of the slotted ring 1303 of the toolring assembly 1003, where the slot is so tapered as to retract andextend each shoe when desired by the rotation of the slotted disc. Eachbead/lock shoe includes a beading roller head 1405 a and a cuttingroller head 1405 b holding beading roller 1406 and a cutting roller1407, respectively. The roller heads are adjustable within the bead/lockshoe with reference to the slotted block by shims (not shown)independently of the fixed offset slider. The bead/cutter tool set hasbeen simplified, where most components other then the “slide spacer” and“slide base” are common regardless of OD part sizes, reducing theoverall cost of a multi OD machine setup.

Referring to FIG. 30, the drum drive assembly 1005 includes a supportflange 1501, three slide bearings 1502 and lockrings 1521 mounted atcorners of the support flange, an irising clamp assembly 1503 mountedwithin the support flange, a multi-size locking drum assembly 1504mounted coaxially with the irising clamp assembly below the supportflange, a pulley drivetrain 1505 connecting the locking drum 1504 to adrum motor (not shown) mounted on a motor bracket 1506. The irisingclamp assembly includes an outer ring 1531 held to the support flange1501 by clamps 1532, an inner ring 1533 driven within the outer ring bythe locking drum assembly 1504, and a plurality of clamp heads 1534mounted to the outer ring and slidable in spiral tracks of the innerring. The multi-diameter part retainer drum 1504 includes a plurality ofvarious sized rings 1541 that are movable by the driven sprocket 1551 ofthe pulley drivetrain, the uppermost ring being connected to theomni-directional irising clamp assembly 1503 and the lowest ring beingconnected to the driven sprocket. The drum drive is designed to rotatecontinuously in either direction. This allows the drum drive to be usedas a secondary rotation device, rather than having to mount a secondmotor outside the machine for pre-bending elbows. The inner and outerrings and the spiral tracks of the irising clamp assembly 1503 arearranged so that, as the locking drum assembly 1504 rotates in onedirection, the clamp heads expand from a minimal diameter toward amaximal diameter, and then back toward the minimal diameter, as the partretainer drum assembly 1504 is rotated continuously in either directionby the pulley drive; reversing the part retainer drum rotation causesthe irising clamp to expand from its present diameter, then contractagain. This radial oscillating motion eliminates having to dismantle anytooling within the body of the machine to change elbow workpiece partdiameter. Since the drum drive 1005 includes a multi-size locking drumassembly 1504, the only tool changeouts for changing elbow sizes are thebead/lock shoe mounted onto the tool ring subassembly and the slideblock 1008 mounted onto the arbor head 1007.

Referring to FIG. 31, the arbor column 1006 is mounted through andsubstantially perpendicular to the baseplate 1016. As can best be seenby referring back to FIG. 24, the baseplate 1016 is substantiallyperpendicular to the tube axis, that is, angled at about fifteen (15)degrees from the top plate 1002 and the tool ring 1003. Consequently thearbor column 1006 is disposed substantially parallel with the tube axis,angled at about fifteen (15) degrees from the cut axis defined by thethrough-hole 1021. The arbor column serves as a locating post for theelbow workpiece 24, which is inserted into the through-hole over thearbor column. Referring again to FIG. 31, the arbor column also supportsand houses the arbor head 1007 and the associated drive traincomponents, as further discussed below with reference to FIG. 32.

Referring to FIG. 32, the arbor head 1007 is designed to have a fifteen(15) degree tilt upper surface with a jointless drive train extendingslantwise across the arbor axis defined by the arbor head subassembly.This is by contrast to previous implementations where universal jointswere used and resulted in significant vibrations due to continualslow-and-go accelerations. The jointless drive train provides much lessvibration and thereby reduces the creation of slivers, enhancing safetyand finished elbow quality. The fifteen (15) degree tilt upper surfaceis substantially parallel with the tool ring 1003. The arbor headincludes an outer shell 1701, upper and lower drive train portions 1702a, 1702 b respectively, a pinhead 1704, a split support block 1705. Theouter shell includes a ring bushing 1711 for enhanced rotation of thesplit support block relative to the outer shell, a sequence of bushings1712, 1713, 1714 for locating the upper drivetrain 1702 a, at least oneside groove 1715, an offset hole 1716, a bottom plate 1717. The upperdrive train 1702 a includes a top shaft 1721 protruding through thesplit support block, a midshaft 1722, assembly components 1723, and alower shaft 1726. The pinhead is mounted to the upper end of the topshaft and rests on the split support block. The top shaft extendsdownward from the pin head parallel with the midshaft and at a fifteen(15) degree angle from the centerline of the outer shell and the arborcolumn 1006. The top shaft defines an arbor axis substantiallycoincident with the cut axis defined by the through-hole 1021; thepinhead rotates about the arbor axis. The midshaft is offset across thecenterline of the arbor column from the top shaft and at its upper endis operatively connected to the top shaft by a first offset gear pair1724 and 1725 carried on the top shaft and on the midshaft,respectively. The midshaft at its lower end is operatively connected tothe lower shaft by a second offset gearset 1727 carried on the midshaftand on the lower shaft, respectively, so that the lower shaft also isoffset from the midshaft across the centerline of the outer shell and isdoubly offset from the top shaft. Like the top shaft and the midshaftthe lower shaft extends at a fifteen (15) degree angle across thecenterline of the arbor column 1006 and the lower end of the lower shaftprotrudes through the shell of the arbor column. The lower shaft carriesa beveled pinion 1726 at its lower end. The beveled pinion is beveled ata fifteen (15) degree angle so that the flanks of the pinion teethextend substantially parallel with the centerline of the arbor column.The beveled pinion is driven by a straight-flanked (zero bevel) ring orbull gear also having tooth flanks extending substantially parallel withthe centerline of the arbor column, thus permitting slight axialadjustments of the arbor column 1006 to compensate for varyingthicknesses of sheet metal being worked without disengagement of thearbor head drivetrain. The ring gear or bull gear can be powereddirectly or indirectly by an electric motor. As will be appreciated bythose of ordinary skill, the beveled teeth of the pinion mean thatupward adjustment of the arbor head for thinner sheet metal consequentlywill result in slightly faster rotation of the pinhead, while downwardadjustments for thicker sheet metal will result in slightly slowerrotation of the pinhead. This “fine tone” linear travel of the arborcolumn 1006 adjusts the cutter disc of the slide block 1008 to a definedgap (based on part wall thickness) from the cutter blade of thebead/lock shoe 1004. This adjustment allows for different wallthicknesses regardless of OD, as to reduce all “metal shaving”. Thesplit support block permits rapid change-out of the quick-change slideblock 1008 so that the arbor head can be used for different sizes ofsheet metal cylinders, eliminating previously complex retooling of anentire arbor head required in order to changeover to a different partsize.

Referring back to FIG. 29, the bead/lock shoes 1004 can be madeinterchangeable with the slide blocks 1008 for use on the arbor head1007. The slide block includes first and second tool shoes 1805 a, 1805b, having a cutting wheel 1806 in one shoe and a beading wheel 1807 inthe other shoe. With the slide block mounted on the pinhead 1704, thewheels 1806 and 1807 are disposed substantially coplanar with theircorresponding rollers 1406 and 1407. The offset pin 1741 on the pinhead1704 drives the slide block 1008 back and forth to provide cutting andbeading steps successively, with each of the wheels 1806, 1807 beingsuccessively exposed to perform these operations as the pinhead rotates.Alternatively, the dual slide block head 106 (shown in FIGS. 18 and 19)can be used as the slide block 1008. In either embodiment, the top shaft1721 of the upper drivetrain 1702 is positioned to extend through thesupport block 1705 and is coupled to the pinhead 1704 for driving theslide block. To cut and preform the workpiece 24, the offset pin 1741 isinitially centered within the slot of the slide block, and the cuttingwheel is then moved out into engagement with the interior of the workpiece, and cooperates with the cutting roller 1406 of the tool shoe 1004to cut the work piece. To couple the cut portions, the slide block movesto expose the beading wheel after the cut pieces of the tube arepositioned in overlapping relationship. In cooperation with the beadingroller 1407, the bead coupling is formed between adjacent cut sections.

While the invention has been described with reference to the preferredembodiments, it will be understood by those skilled in the art thatvarious obvious changes may be made, and equivalents may be substitutedfor elements thereof, without departing from the essential scope of thepresent invention. For example, although three distinct embodiments havebeen shown and described, aspects of the three embodiments can becombined in various ways without undue experimentation. Therefore, it isintended that the invention not be limited to the particular embodimentsdisclosed, but that the invention includes all embodiments fallingwithin the scope of the appended claims.

1. An apparatus for forming an elbow from a sheet metal tube with anouter diameter within a predetermined range of diameters, said apparatuscomprising: a frame defining a vertical axis and a tube axis offset fromthe vertical axis by a tube angle; a top plate, mounted to the top ofsaid frame, with a through-hole defining a cut axis offset from the tubeaxis by a cut angle; a tool ring rotatably mounted to said top platesubstantially coaxial with and surrounding the through-hole; a tool shoeslidably mounted to said tool ring for radial motion toward and awayfrom the cut axis across the through-hole, according to the diameter ofsaid sheet metal tube, rotation of said tool ring within said top platecausing the radial motion of said tool shoe; a baseplate supportedwithin said frame below said top plate and substantially perpendicularto the tube axis; a locking drum assembly supported within said framebetween said top plate and said baseplate and substantially coaxial withthe tube axis, said locking drum assembly including clamp heads forgripping said sheet metal tube, the clamp heads being radially movablewithin said locking drum assembly toward and away from the tube axisaccording to the diameter of said sheet metal tube, and the locking drumassembly being rotatably movable within said frame by means of a lockingdrum motor; an arbor column mounted to said baseplate substantiallyparallel with the tube axis; an arbor head mounted to said arbor column,said arbor head including a pinhead rotatable about an arbor axissubstantially parallel with the cut axis; a slide block slidably mountedon said arbor head, rotation of the pinhead causing radial motion ofsaid slide block toward and away from the arbor axis; and a jointlessdrivetrain extending from the pinhead of said arbor head through saidarbor column, substantially parallel with the cut axis and to the arboraxis, and operatively connecting the pinhead to a motor.
 2. Theapparatus as claimed in claim 1, wherein the tube angle is about thirty(30) degrees.
 3. The apparatus as claimed in claim 1, wherein the cutangle is about fifteen (15) degrees.
 4. The apparatus as claimed inclaim 1, wherein the cut angle is about twenty two and one half (22.5)degrees.
 5. The apparatus as claimed in claim 1, wherein said tool shoeis selected from one of a plurality of tool shoes interchangeablyconnectable to said tool ring, according to the diameter of said sheetmetal tube.
 6. The apparatus as claimed in claim 1, wherein said lockingdrum assembly includes an irising clamp having an outer ring and aninner ring, the clamp heads being slidably connected to the outer ringand slidably pivotally connected to the inner ring for radiallyoscillating motion as said locking drum assembly rotates within saidframe continuously in a single direction about the tube axis.
 7. Theapparatus as claimed in claim 1, wherein said jointless drivetrainincludes a sequence of offset shafts extending substantially parallelwith the cut axis operatively connected by offset gearsets, the lowestshaft of the sequence terminating in a beveled pinion gear having toothflanks that are substantially parallel with the tube axis at a locationwhere the beveled pinion gear meshes with a driving gear.
 8. Theapparatus as claimed in claim 1, wherein said tool ring includes anouter ring clamped to said top plate, a slotted ring having a spiralslot and rotatably mounted within the outer ring, and a motoroperatively connecting the slotted ring to the outer ring, and said toolshoe is radially slidably mounted to the outer ring of said tool ringand is slidably engaged with the spiral slot of the slotted ring, sothat rotation of the slotted ring within the outer ring causes inward oroutward radial motion of said tool shoe.
 9. The apparatus as claimed inclaim 8, wherein said spiral slot provides for about one (1) inch radialmotion of said tool shoe.
 10. The apparatus as claimed in claim 8,comprising first, second and third tool shoes respectively engaged withfirst, second, and third spiral slots equally circumferentially spacedaround the slotted ring of said tool ring.
 11. The apparatus as claimedin claim 8, further comprising a control module operatively connected toselectively actuate the motor of said jointless drivetrain, the motor ofsaid locking drum assembly, and the motor of said tool ring.
 12. Theapparatus as claimed in claim 11, wherein at least one of the motors isa hydraulic motor.
 13. The apparatus as claimed in claim 11, whereinsaid control module is programmed to cut and bead three fifteen (15)degree joints at substantially equal spacings along said sheet metaltube, upon insertion of said tube through the through-hole of said topplate to contact said baseplate.
 14. The apparatus as claimed in claim13, wherein said control module is actuated to execute its program bycontact of said tube against said baseplate.
 15. The apparatus asclaimed in claim 13, said arbor column further including a limit switch,wherein said control module is actuated to execute its program byactuation of the limit switch.
 16. The apparatus as claimed in claim 1,wherein said arbor column is movable relative to said baseplate alongthe tube axis, said jointless drivetrain being driven by a beveledpinion gear having tooth flanks that are substantially parallel with thetube axis at a location where the beveled pinion gear meshes with adriving gear.
 17. The apparatus as claimed in claim 1, wherein the tubeangle is negligibly small such that the tube axis is parallel with thevertical axis.